Screw-nut.



ENCE.

ATENT :WILLIAM n. CROSBY, OF BUFFALO, NEW YORK', ASSICNOR ToV THE CROSBYCOMPANY, OE SAME PLACE.

'SCREW-NUT..

lSPECIFIGA'L101`1'tfol'flltgpart Of Letters Patent N0. 680,991, dated.August'20, 1901.

Application led May I 1901. Serial No. 60,324. (No model.)

`To. all whom t may concern: I

Be it known thatl, WILLIAM H. CROSBY, a citizen of the United States,residing at Buffalo, in the county of Erie and State of New .Yorin haveinvented a new and useful Improvement in `Screw-Nuts, of which thefollowing is a Specification.

This invention relates generally to screwnuts, and more particularly tothe class of nuts `which are commonly known as cap-nuts and which areprovided at their crown or outer end with an inwardly-turned lip adaptedtoA i overlap theend of a tube or other member or a shoulder of themember to which the nut is applied for forming a neat finish. My invention has more especial reference to a cap-- nut stamped from sheetmetal and to a method of making the same. Heretofore it has beenattempted to make such nuts partly of sheet metal by stamping acupshaped blank or crown with a cap-flange at its small end and l Fahexagonal socketat its large end and driving an ordinary screw-nut intothis socket.

` Cap -nuts comprising .two pieces have also l so` r pieces and which isfree from the Objections above stated.

been constructed by stamping the body of the nut from a blank anddriving a sheet-metal .r g `cap or iianged collar upon the reducedcylinx "drical portion of the stamped-nut body. Both Iof theseconstructions are comparatively eX- pensive, and the 'two parts of thenut are The object of my invention is the produc cheaper than nutsmachined from a solid bar of metal and those composed of a number of Inthe accompanying drawings, Figure l is `a perspective view of the.fiat.V blank from `,which my improved nut is stamped. Figs.

2, 3, and 4. are sectional elevations of different sets of dies whichare employed for forming the nut, showing the shape of the blank atdifferentstages of the stamping operation.

Fig. 5 is a longitudinal central section of the completed nut. Fig. 6 isa bottom plan view f of the same.

Like letters of reference refer to like parts in the several figures.

portion of my improved cap-nut, havinga projecting hexagonal rim a', anda2 is its crown portion, having an inwardly-turned lip or flange a3,which forms the cap of the nnt. The nut is stamped in a single piecefrom a flat blank of sheet metal, such as sheet-steel. The base portiono. of the nut, in which the greater portion of its screw-thread is cut,is thicker than the original thickness of the blank, while the crownportion a2 may be thinner than the original thickness of the blank, asshown.

In making my improvedcap-nut a flat sheet-metal plate or blank B ofcircular form is first cut or punched, and this blank is stamped betweensuitable male and female dies C C to approximately the shape of atapering cup, with a convex bottom and aproing the deeper set. Acircular hole somewhat smaller than the bore or internal diameter of thescrew-threaded portion of the finished nut is next punched centrally inthe bottom of the cup-shaped blank by suitable dies D D', as shown inFig'. 3. The rim of the perforated blank is then trimmed OE to reduceits diameter, and the blank is further stamped be tween dies E E ofsubstantially the shape of `the preceding dies, but Shallower and largerin diameter than the same, as shown in Fig. 4. The bottom of the femaledie E is substantially horizontal, and the lower portion of the maleQdie E is stepped to formupper and lower annular shoulders e c. of themale die between these shoulders is somewhat larger in diameter than thecorresponding portion of the male die D of the preceding set, and theportion e3 of the male die E below its lower shoulder e is somewhatsmaller in diameter than the corresponding portion of the male die D.The upper portion of the male die is surrounded by acollar or stripperE2, which descends with the same and which has its under side arrangedflush The portion e2V IOO inwardly to form the cap-Harige as `of thenut,

and the blank is at vthe same time upset or compressed lengthwise to theform shown in" Fig. 4, the same being reduced in height and enlarged indiameter, its walls thickened, andy themetal condensed. A The collar E2,descending upon the rim portion of the blank, aids in upsetting theblank and confines the metal in the upper portion of the female die. Theblank may be gradually upset to the form shown in Fig. 5 by two or moresets of dies made successively shallower and wider. A screw-thread isnext cut in the Vring-shaped nut-blank so formed, and the rim of theblank is finally punched by suitable dies to the hexagonal form shown inFig. 6, or, if desired, the saine may be left circular or flattened onlyat opposite points ory otherwise suitably formed to receive'a wrench orother toolfor turning the nut. Before threading the nut the portion ofits bore'adjacent to its cap-flange a may be undercut by a suitabletool, las shown in Fig. 5.

By stamping the nut asabove described its base portion, in which thegreater part of the screw-thread is cut and which is subjected to thegreatest strain, is thickened beyond the original thickness of the flatblank, providing a suicient amount of stock in that part of the nut forcutting the screw-thread without sacrificing the strength of the nut. Anut practically as strong and of as sightly dimensions as a nut machinedfrom a solid bar is thus produced from a blank of mini- ,mum thicknessand at a much smaller cost than that of a machined nut or one composedof two stamped members or partly of a machined member and partly of astamped member, and as the improved nut is stamped of an integral pieceit has none of the objections of a two-piece nut.

While I have herein shown and described my improvement as applied to acap-nut, the feature of providing an integral sheetmetal nut with athickened base portion is equally applicable to nuts un provided with acap-flange. p

I claim as my inventionl. A screw-nut pressed from an integral blank ofsheet metal and having its screwthreaded base portion upset forthickening the same, substantially as set forth.

2. Ascrew-nut pressed from an integral blank of sheet metal and providedat its crown with an inwardly-turned cap-lip and having itsscrew-threaded base portion thickened by upsetting the same betweensuitable dies, substantially as set forth.

3. A screw-nut pressed from an integral blank of sheet metal andprovided at its crown with an inwardly-turned cap-lip, the capped crownportion of the nut being stamped of lesslthickness and its base portionupset to a greater thickness than that of the blank, substantially asse't forth.

4. A nut-blank pressed from an integral plate of sheet metal, andconsisting of a rind provided at one end with an inwardly-turne cap-lipand at its opposite end with a projecting rim and having the portionthereof adjacent to said rim upset to a greater thickness than that ofthe plate from which the nut-blank is pressed, substantially as setforth. Y 5. The herein-described method of making an integralsheet-metal nut-blank, which consists in stam pin ga flat plate or blankapproxi` mately to the form of a cup, then forming an opening in thebottom of the cup, and. then thickening the wall of the perforated cupby upsetting the same between suitably-shaped dies, substantially as setforth.-

6. The herein-'described method of making an integral, sheet-metalcap-nut, which consists instamping a flat blank approximately to theform of a cup,- then forming in the bottom of the cup an opening ofsmaller diameter than the bore of the completed nut,

and finally thickening the Wall 'of the per-v forated cup by upsettingthe same between suitable dies and at the same time turning form thecap-ange of the nut, substantial] asset forth.

Witness myhand this 8th day of May, 1901.

WILLIAM H. CROSBY.

Witnesses:

A. D. DANA, CARL F. GEYER.

`the perforated end of the cup inwardly to

